Fix startup and GPT initialization issues

backend/app/gpt/universal_gpt.py

@@ -14,7 +14,6 @@ class UniversalGPT(GPT):
         self.model = model
         self.temperature = temperature
         self.screenshot = False
-        self.screenshot = False
         self.link = False
 
     def _format_time(self, seconds: float) -> str:

backend/main.py

@@ -40,7 +40,6 @@ async def startup_event():
     register_exception_handlers(app)
     register_handler()
     ensure_ffmpeg_or_raise()
-    register_handler()
     get_transcriber(transcriber_type=os.getenv("TRANSCRIBER_TYPE","fast-whisper"))
     init_video_task_table()
     init_provider_table()